1. Field of the Invention
The present invention relates to a blackhead removing agent for removing blackheads which include keratin, sebum, dirt or the like clogging the pores of the skin. The present invention also relates to a blackhead removing sheet, and to a method for producing such a blackhead removing sheet.
2. Description of the Prior Art
Peel-off types of blackhead removing agents and sheet types of blackhead removing agents have recently been proposed for removing blackheads or dirt in pores.
First, the prior art relating to peel-off types of blackhead removing agents will be described.
Peel-off types of blackhead removing agents are used in the following manner. A liquid blackhead removing agent is first applied by hand onto the face or the like. The applied blackhead removing agent is then left alone to dry. Thereafter, the dried blackhead removing agent is peeled off.
However, a problem with such peel-off types of blackhead removing agents is that the fingers become soiled by the blackhead removing agent when it is applied. Another problem is that it is relatively difficult to evenly apply the blackhead removing agent on the face. Yet another problem is that it takes a long time to allow the applied blackhead removing agent to dry. Still another problem is that part of the blackhead removing agent tends to remain on the skin when the dried blackhead removing agent is peeled off of the face.
Sheet types of blackhead removing agents (blackhead removing sheets) have thus been proposed to remedy the problems related to the aforementioned conventional peel-off types of blackhead removing agents, and to make it easier to remove blackheads. Such blackhead removing sheets comprise a layer composed of a base material (base material layer) and a layer composed of a blackhead removing agent (blackhead removing layer), which are laminated together.
Next, the prior art related to sheet types of blackhead removing agents is described below.
One example of sheet types of blackhead removing agents (blackhead removing sheet) has been disclosed in Japanese Laid-open Patent Application (Kokai) 10-77212. A liquid plasticizer that is compatible with the water-soluble macromolecular compound serving as a primary component and that imparts plasticity is added to the blackhead removing agent of this blackhead removing sheet in order to keep the blackhead removing layer from becoming too hard. Glycerin, 1,3-butanediol, and the like have been used as plasticizers. When such a plasticizer is added to the blackhead removing agent, the blackhead removing layer can be effectively prevented from becoming too hard.
However, such blackhead removing sheets suffer from the following problems.
One problem with conventional blackhead removing sheets is the insufficient strength of the blackhead removing layer after it has dried.
High adhesive strength for blackheads cannot be obtained in the aforementioned blackhead removing sheet since the blackhead removing agent has been plasticized by the addition of a plasticizer. Thus, a problem with such conventional blackhead removing sheets is that blackheads cannot be sufficiently removed.
Further in general, hydrophilic plasticizers exhibit poor volatility or nonvolatility from room temperature to around body temperature. Therefore, in the case of conventional blackhead removing sheets, the blackhead removing sheet must be left for long periods of time to allow the blackhead removing layer to dry. It is thus inconvenient for a user to leave the blackhead removing sheet on for long periods of time.
Next, problems involved in the use of woven fabrics and the like as the material for the base layer of such blackhead removing sheets are described below.
The blackhead removing layer of blackhead removing sheets must be kept moist when the blackhead removing sheet is used. In other words, the blackhead removing layer of the blackhead removing sheet must contain water when the blackhead removing sheet is used.
However, the blackhead removing layer is softened by moisture when the blackhead removing layer of the blackhead removing sheet contains water. The blackhead removing agent of the softened blackhead removing layer penetrates deeply into the gaps between the fibers in woven fabrics. As a result, the blackhead removing layer of the blackhead removing sheet can no longer adequately adhere to the skin. In other words, the blackhead removing layer can no longer adequately adhere to blackheads. Therefore, involve a problem in the blackhead removing capabilities are the conventional blackhead removing sheets.
In addition, the blackhead removing agent of the softened blackhead removing layer penetrates deeply into the gaps between the fibers of woven fabrics, so that the blackhead removing agent exudes from the outer surface of the base layer. A resulting problem is that the blackhead removing agent which is exuded from the outer surface of the base layer sticks to the fingers when the blackhead removing sheet applies to the skin, for example.
The use of a thick base layer as the base layer for blackhead removing sheets has been attempted as a means for remedying such problems involved in the conventional blackhead removing sheet described above. Such thick base layers do allow the blackhead removing agent to be prevented from exuding out of the surface of the base layer. On the other hand, however, there is a problem in that the base layer suffers a loss of flexibility. The blackhead removing sheets having such base layers that lack in flexibility involve problems in the conformability of the blackhead removing sheets with the skin, their adhesion to the skin, and their blackhead removing capabilities.
An object of the present invention is to provide a blackhead removing agent having excellent blackhead removing capabilities.
Another object of the present invention is to provide a blackhead removing agent that can be rapidly dried.
Still another object of the present invention is to provide a blackhead removing sheet having excellent conformability to the curved surface.
Yet another object of the present invention is to provide a method for producing a blackhead removing sheet having excellent conformability to the curved surface.